Membrane loud-speaker for radio apparatus, gramophones, and the like



March 19, 1929. Rn- 1,706,323

MEMBRANE LOUD SPEAKER FOR RADIO APPARATUS, GRAMOPHONES, AND THE LIKE Filed 001;. 1926 [wash/5r Max ZPz'ffer Patented Mar. .19, 1929.

MAX BITTER, F BASEL, SWITZERLAND.

MEMBRANE LOUD-SPEAKER FOR RAJD IO APPARATUS, GRAMOPHONES, AND THE LIKE.

Application filed October 4, 1926, Serial No. 139,517, and in Switzerland October 15, 1925.

correct waves together with the extension part of the receiving membrane and do not 've preference to disturbing harmonic oscil ations. If this is so, then the sound waves, when passing through the trumpet tube, are always brought by means of the membrane extension to correct oscillation, so that great olearness in the reproduction of sound is obtained.

' 'The accompanyin' drawing illustrates difi'erent examples 0- carrying out the invention.

Fig. 1 is a front view of one half papt with the membrane removed, and

Fig. 2 a transverse section of one form of construction which comprises two sound trumpets with trumpet passages spirally Wound.

Fig. 3 is a section across a similar form in which, however, the trumpet passages are situated radially to the membrane box.

struction similar to that of Figs. 1 and 2, showing a rectangular 'orosssection of the trumpet.

Figs. 5 and 6 show by views correspond- 40 mg to Figs. 1 and 2 a constructional form with one unilateral trumpet only.

Fig. 7 is-a detail view of a 3 on a larger scale.

According to Figs. 1,2, and 4, a is a mem- 4 brane and b the-receiver influencin the latter, whilst a, 0 represent two sound trumpet passages wound spirally round the membrane box. (1, which passages are arranged part of Fig.

on both sides of the membrane a. The latter is extended outside the box room at f in such manner that it forms, by its extension 7, a portion of the passage walls of the two sound trumpets. At the clamped-in parts of the membrane a, care must be taken that the extension part of the same is capable of oscillating with it, so that by such harmonic simultaneous oscillation of the extension of the membrane an intensification of the reproduction of sound is obtained.

In Fig. 3 the sound trumpet passages c, c are directed radially to the membrane box cl, instead of being s irally wound. a is the membrane and b t e receiver. 7 is an extension or continuation of the membrane w; it forms here a part of the wall common to both trumpet passages 0,, 0

Fig. 4 shows an arrangement similar to that illustrated in Figs. 1 and 2, but the two spirally wound passages c, 0 are constructed of a rectan lar cross section.

In the execution s own in Figs. 5 and 6, v i

,manner that it forms a part of the wall of the trumpet passa e 0 which is capable of oscillating. b is t e receiver.

What I claim is 1- A membrane loudspeaker for'radio ap- Fig. 4 is a trumpet end view of a conparatus, gramophones and the like, comprising a receiver, a receiving box adjacent thereto, a membrane within the latter, at least one sound trumpet connected to said membrane box and an oscillating extension on said receiving membrane forming part of the wall of said sound trumpet to improve or intensify the reproduction of the sound.

In witness whereof I have hereunto sign- ;d ny' name this 23rd day of September,

MAX BITTER. 

